CASTOR LOCKING DEVICE

Abstract: A castor locking device (10) for a trolley (14) which when activated by manual deployment of the operating lever (18) locks selected castors in the fore and aft position. When the castor locking device (10) is locked, the trolley operator is able more easily to steer and manoeuvre the trolley (14).

Description: "Castor Locking Device" This invention relates to a castor locking device. Shoppers require that trolleys in which shopping- is placed, generally found in supermarkets, behave in an easily controllable manner. Trolleys often behave in a manner which is difficult to control when they are heavily laden or when travelling down a slope, for example to a car park or other area. A number of devices are known which lock the castors of a trolley in one position which are dependent on the load on the trolley. Devices are also known which are manually operated and which can selectively lock or unlock the castors in a given direction. The known devices have the disadvantage that the trolley operator has to remember whether the castors are locked or rotating freely and operate the locking mechanism accordingly. According to the present invention there is provided a- castor locking device for a trolley comprising first and second members, said first member being attachable to a carrying member of the trolley, said second member being attachable to a wheel of the trolley and rotationally connected to said first member, and locking means are provided for locking the two members in a predetermined position by operation of a control means wherein the locking means are only activated during the operation of the control means. Preferably, the first member is in fixed relation to a carrying member of the trolley and the second member is in fixed relation to the wheel. Preferably, the first and second members are rotationally connected by means of bearings disposed between the members. Preferably, the locking means for selectively locking the first and second members is in the form of a catch which when operated interacts with the first and second members preventing relative rotation of the members. Preferably, the control means is operated by a lever disposed at a handle of the trolley. Preferably, the control means is sprung such that, when the lever is operated and the locking means selected, the locking means locks the first and second members only when they are in their predetermined position. Preferably, release of the control means releases the locking means. According to a second aspect of the present invention, there is provided a trolley comprising a carrying member, a handle and wheels any or all of which have a castor locking device of the first aspect of the present invention. Embodiments of the present invention will now be described with reference to the accompanying drawings, in which: Fig la is a side view of a castor locking device according to the present invention in an unlocked position; Fig lb is a side view of the castor locking device of Fig la in a locked position; Fig 2a is a rear view of the castor locking device of Fig la; Fig 2b is a plan view of the castor locking device of Fig la; Fig 3a is a plan view of an embodiment of a castor locking device in accordance with the present invention with an alternative catch arrangement; Fig 3b is a side view of the castor locking device of Fig 3a; Fig 4a is a rear or front view of the castor locking device of Fig 3a; Fig 4b is a perspective view of the castor locking device of Fig 3a; Fig 5 is a side view of a trolley with a castor locking device of Fig 1; Fig 6 is a front view of the trolley of Fig 5; Fig 7a, b and c are schematic side views of a first embodiment of the castor locking device of Fig 1 in an unlocked, selected and locked position; Fig 8a, b and c are schematic side views of a second embodiment of the castor locking device in accordance with the present invention in an unlocked, selected and locked position; and Fig 8d is a plan of the castor locking device of Fig 8a. Referring to the drawings, there is a castor locking device 10 for a trolley 14 which has a first member 1 and a second member 2, the first member 1 being in a fixed relationship with the basket 16 of the trolley 14. The second member 2 rotates in relation to the first member 1 and the second member 2 supports the axle and wheel of a castor of the trolley 14. Means are provided for selectively locking the two members 1 and 2 in the form of a locking device 4 with a locking catch 6 which prevents the relative rotation of the two members 1 and 2. The locking catch 6 is pivotally mounted on the first member 1 at a pivot point 23 and in the first embodiment of the invention the catch 6 is in the form of a bar 24 which engages in a slot 8 on the second member 2 when the catch 6 is operated by an operating lever 18. The two members 1, 2 rotate by means of a plurality of bearings 3 between the first and second members 1, 2. The slot 8 in the second member 2 is aligned with the catch 6 on the first member 1 only when the castor of the trolley 14 is in a fore and aft position in relation to the trolley 14, with the axle 25 of the castor in a position orthogonal to the fore and aft position of the trolley 14. The catch 6 is attached to a control rod 5 with a spring arrangement, the control rod 5 is attached to an operating lever 18 located on the steering handle 22 of the trolley 14. The operating lever 18 must be positively operated and the catch 6 is biased to ensure that the catch 6 springs into the slot 8 in the second member 2 as soon as the first and second members 1, 2 are aligned and the castor is in the fore and aft position. This will occur regardless of the position of the castor at the time when the operating lever 18 is activated. The control rod 5 can be in the form of a cable, push/pull rod, rotary shaft or a combination of these arrangements. A second embodiment of a catch 6 is shown in Fig 3a to 4b in which the catch 6 is in the form of a fork 26 which, when in the locked position surrounds a lug 27. The lug 27 is disposed on or is formed as an integral part of the second member 2. The fork 26 and lug 27 arrangement of the locking device 4 operates in a similar manner to the bar catch 24. Both arrangements employing a basic male/female engagement principle. As a trolley 14 is pushed forward the castors trail to the fore and aft position. Just before reaching the fore and aft position the lug 27 pushes the fork 26 outwards until engagement takes place. A first embodiment of the spring arrangement is shown in Fig 7a, b and c and has a springbox 13 disposed at a point in the control rod 5. When the operating lever 18 is in a released position (Fig 7a) the spring 20 of the springbox 13 is in an unstretched position. The operating lever 18 can be manually selected and this tensions the spring 20 and biases the catch 6 towards the second member 2, the catch 6 then springs into the slot 8 in the second member 2 when the first and second members 1,2 are in the aligned position (Fig 7c) . When the catch 6 is in the slot 8, the spring 20 remains semi-tensioned. When the operating lever 18 is released, the spring 20 springs back to its compressed position and the catch 6 disengages the slot 8. A second embodiment of the spring arrangement is shown in Fig 8a, b, c and d. In this embodiment the spring is in the form of a rotary spring 21 which biases the catch 6 in an open position. When the operating lever 18 is operated the rotary spring 21 is activated by the control rod 5 via a spring lever 19 such that the catch 6 is biased towards the slot 8 as before. The release of the locking device 4 can be achieved by gravity or the weight of the steering lever 18 or other components of the device 10. It is an important feature that the locking device 4 is only in operation during the time that the operating lever 18 is being positively deployed. If the operator releases the operating lever 18 the locking operation is terminated and the catch 6 will disengage the slot 8. When the catch 6 is not in the locking position the castor is free to swivel through 360 degrees. Each one of the front and rear castors of a trolley 14 can have a castor locking device 10 and the operation of the operating lever 18 can be arranged to operate all the locking devices 4 on all castors or just the rear or front castors or each castor individually and each selected castor will lock only when it is aligned in the fore and aft position. An empty or laden trolley 14 can have the capability, by manual selection of the operating lever 18, to lock a castor, front or rear, in the fore and aft position. Especially with a laden trolley, the locking of the castors aids steering and prevents the trolley 14 from drifting out from a given direction when cornering and drifting downslope when traversing sloping ground. The castor locking device 10 can utilise an existing castor and only comes into operation when selected by the trolley operator. The operating lever 18 is located under the steering handle 22 and is activated by pulling up on the lever 18. On release of the operating lever 18 the castor reverts to its fully swivelling position. The control rod 5 linking the operating lever 18 to the catch 6 of the castor locking device 10 can be contained inside the chassis of the trolley 14. The device 10 does not affect stacking or movement of trolleys 14 in a 'train'. The device 10 is also enclosed in a gaiter to prevent dirt and water from entering the device 10 and this gaiter also acts as a bumper. An adjoining castor, if not fitted with a device 10, would be fitted with a corresponding gaiter or bumper. The device 10 allows a trolley operator to simply select positive steering or free castoring and thereby obtain greater control of the trolley 14. When the device 10 is not locked the castors are free to swivel and the trolley 14 can be pulled in any direction as required, in a supermarket. However, where required locking of some or all of the castors provides ease of manoeuvrability.

Claims: CLAIMS 1. A castor locking device (10) for a trolley (14) comprising first and second members (1, 2) said first member (1) being in attachable to a carrying member (16) of the trolley (14) , said second member (2) being attachable to a wheel of the trolley (14) and rotationally connected to said first member (1) , and characterised in that locking means (4, 6) are provided for locking the two members (1, 2) in a predetermined position by operation of a control means (5) wherein the locking means (4, 6) are only activated during the operation of the control means (5) . 2. A castor locking device (10) for a trolley (14) as claimed in Claim 1 wherein said first member (1) is in fixed relation to the carrying member (16) of the trolley (14) and said second member (2) is in fixed relation to the wheel of the trolley (14) . 3. A castor locking device (10) for a trolley (14) as claimed in Claim 1 or 2 wherein said first (1) and second (2) members are rotationally connected by means of bearings (3) disposed between said members (1, 2) . 4. A castor locking device (10) for a trolley (14) as claimed in any one of Claims 1 to 3 wherein the locking means (4, 6) for selectively locking said first (1) and second (2) members is in the form of a catch which, when operated, interacts with said first (1) and second (2) members preventing relative rotation of the members (1, 2). 5. A castor locking device (10) for a trolley (14) as claimed in any one of Claims 1 to 4 wherein the control means (5) is operated by a lever (18) disposed at a handle (22) of the trolley (14) . 6. A castor locking device (10) for a trolley (14) as claimed in Claim 4 wherein the control means (5) is sprung such that when the lever (18) is operated and the locking means (4, 6) selected, the locking means (4, 6) locks said first (1) and second (2) members only when they are in their predetermined position. 7. A castor locking device (10) for a trolley (14) as claimed in any one of Claims 1 to 6 wherein release of the control means (5) releases the locking means (4, 6) . 8. A trolley (14) comprising a carrying member (16), a handle (22) and wheels in which any or all of said wheels have a castor locking device (10) as defined in any preceding Claim.

Inventors: GRANTHAM JOHN, LOVIE MICHAEL ALEXANDER, GRANTHAM, JOHN, LOVIE, MICHAEL, ALEXANDER
Applicants: GRANTHAM JOHN, LOVIE MICHAEL ALEXANDER, GRANTHAM, JOHN, LOVIE, MICHAEL, ALEXANDER
Application year: 1994
Main classification: B60B33
IPC codes: B60B33